In terms of computer network communications, handshake usually means the process of one computer establishing a connection with another computer or device. The devices can communicate as peer-to-peer mode or as client-server mode. In either case, when computer1 attempts to establish a connection with computer2, computer2 must decide to accept (or deny or ignore) the connection. The handshake is often the steps of verifying the connection, the speed, and/or the authorization of the computer trying to connect to it.
Handshake protocols are a series of technical rules that both parties agree upon. For example, when a connection is initiated by device1, device1 may send a HELLO packet to a specific port on device2. Device2 then, if accepting the connection, sends an ACK packet back to device1. The Handshake protocol is responsible for the negotiation, the initial key exchange, and/or authentication of the two entities.
In order for one device to communicate with another device, both sides must follow the same rules otherwise the communication is doomed to fail. But the problem is the device world is evolving constantly while the handshake protocols, once deployed, are typically static. Protocols that work perfectly today may need modification next month, next week or even the next day because special needs arise. New requirements may imply the needs to change the existing handshake protocol. Once the protocol has been rewritten, there may then be requirements for testing, bug fixing, etc before ultimately deploying the new protocol to existing devices in the field.
What is required is a handshake method that provides dynamic handshake capabilities.